Add event manager as soft dependency to translator
Add enabling event manager in translator to factory
Minot changes to event manager integration in translator
Merge pull request #4187 from DASPRiD/feature/translator-event-manager-integration

Add event manager as soft dependency to translator

Conflicts:
	library/Zend/I18n/composer.json
[#4187] Intercept results of events

- If a string value is returned from the `EVENT_MISSING_TRANSLATION`
  event, we should use it as the translation.
- If a `TextDomain` is returned from the `EVENT_NO_MESSAGES_LOADED`
  event, we should use it for the text domain.
Merge branch 'feature/4187' into develop

Close #4187